Multi-speed transmission

ABSTRACT

A transmission is provided having an input member, an output member, three planetary gear sets, a plurality of coupling members and a plurality of torque transmitting devices. Each of the planetary gear sets includes a sun gear member, a planet carrier member, and a ring gear member. The torque transmitting devices include clutches and a brake arranged within a transmission housing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/828,663, filed on Oct. 9, 2006. The disclosure of the aboveapplication is incorporated herein by reference.

TECHNICAL FIELD

The invention relates generally to a multiple speed transmission havinga plurality of planetary gear sets and a plurality of torquetransmitting devices and more particularly to a transmission havingeight or more speeds, three planetary gear sets and a plurality oftorque transmitting devices.

BACKGROUND

Automatic power transmissions are currently in wide spread use inpassenger vehicles and trucks. As is well known, the automatictransmission provides a plurality of speed ratios in both the forwarddirection and at least one reverse speed ratio. The speed ratios areestablished through the use of a plurality of planetary gearsets. Theengagement of the gearsets is controlled by a number of fluid-operatedtorque-transmitting mechanisms, commonly termed clutches and brakes.

It has become a standard to provide at least four forward speed ratiosin automatic transmissions for use in passenger vehicles. More recently,automobile manufacturers have increased the forward speed ratios to sixand in some instances seven or eight. This, of course, requires theaddition of planetary gearsets. However, it is desirable to minimize thenumber of torque-transmitting mechanisms to reduce cost and overall sizeof the transmission.

A number of the currently proposed eight speed planetary transmissionsprovide three planetary gearsets and five torque-transmittingmechanisms. One problem facing transmission designers and manufacturersis the packaging of the planetary gearsets and the torque-transmittingmechanisms. It is preferable to arrange the gearsets andtorque-transmitting mechanisms in a way that minimizes the overall sizeof the transmission as well as reduces manufacturing complexity.

Thus, there is a need for a new and improved multi-speed transmission.The arrangement of the gearsets and the torque-transmitting mechanismsof the transmission should minimize the size and manufacturingcomplexity of the transmission.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic representation of a cross-section of amulti-speed transmission, in accordance with an embodiment of thepresent invention;

FIG. 2 is a diagrammatic representation of a cross-section of amulti-speed transmission, in accordance with an embodiment of thepresent invention;

FIG. 3 is a diagrammatic representation of a cross-section of amulti-speed transmission, in accordance with an embodiment of thepresent invention;

FIG. 4 is a diagrammatic representation of a cross-section of amulti-speed transmission, in accordance with an embodiment of thepresent invention;

FIG. 5 is a diagrammatic representation of a cross-section of amulti-speed transmission, in accordance with an embodiment of thepresent invention;

FIG. 6 is a diagrammatic representation of a cross-section of amulti-speed transmission, in accordance with an embodiment of thepresent invention;

FIG. 7 is a diagrammatic representation of a cross-section of amulti-speed transmission, in accordance with an embodiment of thepresent invention.

FIG. 8 is a diagrammatic representation of a cross-section of amulti-speed transmission, in accordance with an embodiment of thepresent invention; and

FIG. 9 is a diagrammatic representation of a cross-section of amulti-speed transmission, in accordance with an embodiment of thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, wherein like characters represent the same orcorresponding parts throughout the several views, there is seen in FIG.1 a powertrain 10 having an internal combustion engine or electric motor12, a torque converter or flywheel 14, a transmission 16, and a finaldrive mechanism 18.

The transmission 16 includes an input shaft or member 20, a planetarygear arrangement 22, and an output shaft or member 24. The planetarygear arrangement 22 includes three planetary gearsets 26, 28, and 30,and six selectively-engageable torque-transmitting mechanisms 32, 34,36, 38, 40 and 42. The input shaft 20 is drivingly connected with aconventional turbine disposed within the torque converter 14. The outputshaft 24 is drivingly connected with the final drive mechanism 18. As iswell known in the art of vehicle transmissions, the final drivemechanism 18 provides output shafts to drive the wheels of a vehicle.

The transmission 16 has a first end wall 50, a second end wall 52, and ahousing 54. Housing 54 interconnects between the first and second endwalls 50 and 52 to provide a space or cavity 53 in which the planetarygearsets 26, 28, and 30 and the torque-transmitting mechanisms 32, 34,36, 38, 40 and 42 are located. Further, cavity 53 has a plurality ofzones A, B, C, D and E in which the plurality of torque transmittingmechanisms 32, 34, 36, 38, 40 and 42 will be specifically positioned, inaccordance with the preferred embodiments of the present invention.

As shown in FIG. 1 and throughout the several views, Zone A is definedby the area or space bounded: axially on the left by first end wall 50,axially on the right by planetary gearset 26, radially inward by inputshaft 20 and radially outward by reference line “L” which is alongitudinal line that extends adjacent the planetary gearsets; Zone Bis defined by the area bounded: axially on the left by planetary gearset26, axially on the right by planetary gearset 28, radially inward byinput shaft 20 and radially outward by reference line “L”; Zone C isdefined by the area bounded: axially on the left by planetary gearset28, axially on the right by planetary gearset 30, radially inward byinput shaft 20 and radially outward by reference line “L”; Zone D isdefined by the area bounded: axially on the left by planetary gearset30, axially on the right by second end wall 52, radially inward by inputshaft 20 and radially outward by reference line “L”; and Zone E isdefined by the area bounded: axially on the left by first end wall 50,axially on the right by second end wall 52, radially inward by referenceline “L” and radially outward by housing 54. While reference line “L” isillustrated as a straight line throughout the several views, it shouldbe appreciated that reference line “L” follows the outer periphery ofthe planetary gear sets 26, 28, and 30, and accordingly may be steppedor non-linear depending on the radial location of the outer periphery ofeach of the planetary gear sets 26, 28, 30. As will be described andillustrated hereinafter, planetary gearsets 26, 28 and 30 will changepositions within transmission cavity 53, however, the zones describedabove will not change they will remain the same as shown throughout theFigures.

The planetary gearset 26 includes a sun gear member 60, a ring gearmember 62, and a planet carrier assembly member 64. The planet carrierassembly member 64 includes a plurality of pinion gears 66 rotatablymounted on a planet carrier member 68 and disposed in meshingrelationship with both the sun gear member 60 and the ring gear member62.

The planetary gearset 28 includes a sun gear member 70, a ring gearmember 72, and a planet carrier assembly member 74. The planet carrierassembly member 74 includes a plurality of pinion gears 76 rotatablymounted on a planet carrier member 78 and disposed in meshingrelationship with both sun gear member 70 and ring gear member 72.

The planetary gearset 30 includes a sun gear member 80, a ring gearmember 82, and a planet carrier assembly member 84. The planet carrierassembly member 84 includes a plurality of pinion gears 86 rotatablymounted on a planet carrier member 88 and disposed in meshingrelationship with both the sun gear member 80 and the ring gear member82.

The sun gear member 60 is continuously connected with housing 54 througha shaft 93 that traverses zones A and E. Planet carrier member 88 iscontinuously drivingly connected with output shaft 24. Further, ringgear member 62 is drivingly connected to sun gear member 70 and ringgear member 72 is drivingly connected to sun gear member 80.

The torque-transmitting mechanism 32 may include a servomechanism (notshown), which has a selectively-operable piston (not shown) supported ina housing and adapted to engage one of a plurality of friction discs orreaction plates 100. The reaction plates 100 are disposed tofrictionally engage a plurality of friction discs or reaction plates 102when the torque-transmitting mechanism 32 is engaged. The reactionplates 100 when engaged by the piston will engage the plurality offriction discs 102 to form a frictional engagement between a hub 104drivingly connected with the input shaft 20 and housing 106 connectedwith planet carrier member 68. When the torque-transmitting mechanism 32is engaged, input shaft 20 will be drivingly connected with planetcarrier member 68.

The torque-transmitting mechanism 34 may also include a servomechanism(not shown), which includes a selectively-operable piston (not shown)supported in a housing and adapted to engage one of a plurality offriction discs or reaction plates 112 mounted to housing 115. Housing115 is coupled to ring gear member 72. Reaction plates 112 when engagedby the piston will engage a plurality of friction discs or reactionplates 114 to form a frictional engagement between housing 115 and a hub116 drivingly connected with input shaft 20. When thetorque-transmitting mechanism 34 is engaged, the input shaft 20 will bedrivingly connected with the ring gear member 72 and sun gear member 80.

The torque-transmitting mechanism 36 may also include a servomechanism(not shown) having a selectively-engageable fluid-operated piston (notshown). The piston (not shown) is adapted to engage one of a pluralityof friction discs or reaction plates 120, which when engaged, willfrictionally engage a plurality of friction discs or reaction plates122. The reaction plates 120 are connected through a hub 124 with theinput shaft 20 and friction discs 122 are connected through a hub 126with planet carrier member 78. When the torque-transmitting mechanism 36is engaged, planet carrier member 78 will be drivingly connected withthe input shaft 20.

The torque-transmitting mechanism 38 may also include a servomechanism(not shown) having a selectively-engageable fluid-operated piston (notshown), which is adapted to engage one of a plurality of friction discsor reaction plates 130. When the reaction plates 130 are engaged by thepiston, they will frictionally engage a plurality of friction discs orreaction plates 132. The reaction plates 130 are drivingly connectedwith a hub 134, which is continuously drivingly connected with ring gearmember 82 and friction discs 132 are drivingly connected with a hub 136,which is continuously drivingly connected with planet carrier member 68.When the torque-transmitting mechanism 38 is engaged, planet carriermember 68 and ring gear member 82 will be drivingly connected.

The torque-transmitting mechanism 40 may also include a servomechanism(not shown) having a selectively-engageable fluid-operated piston (notshown), which is adapted to engage one of a plurality of friction discsor reaction plates 140. When the reaction plates 140 are engaged by thepiston, they will frictionally engage a plurality of friction discs orreaction plates 142. The reaction plates 140 are drivingly connectedwith a hub 146, which is continuously drivingly connected with ring gearmember 82 and friction discs 142 are drivingly connected with a housing144, which is continuously drivingly connected with planet carriermember 78. When the torque-transmitting mechanism 40 is engaged, planetcarrier member 78 and ring gear member 82 will be drivingly connected.

The torque-transmitting mechanism 42 includes a plurality of frictiondiscs or reaction plates 160 fixed to a hub 162. Whentorque-transmitting mechanism 42 is engaged, reaction plates 160 willfrictionally engage a plurality of friction discs or reaction plates164. The reaction plates 160 are drivingly connected with a hub 162,which is continuously drivingly connected with ring gear member 82 andreaction 164 are connected to housing 54. When the torque-transmittingmechanism 42 is engaged, ring gear member 82 will be held stationaryrelative to housing 54

From the above description, those skilled in the art will recognize thatthe torque-transmitting mechanisms 32, 34, 36, 38 and 40 are clutchmechanisms and the torque-transmitting mechanism 42 is a brakemechanism. In the engineering field, the disc-type brakes are commonlytermed reaction clutches and the clutch mechanisms are referred to asrotary clutches. The transmission 16 will provide eight forward speedratios and one reverse speed ratio between the engine 12, the torqueconverter 14, and the final drive mechanism 18.

As shown in FIG. 1, planetary gearset 26 is disposed closest to wall 50and planetary gearset 30 is disposed closest to wall 52. Planetarygearset 28 is disposed between planetary gearset 26 and 30.Torque-transmitting mechanisms 32, 40 are disposed in zone “B”. Further,torque-transmitting mechanisms 34 and 36 are disposed in zone “C”. Thetorque-transmitting mechanisms 38, 42 are disposed in zone “E”. Thismakes for a fairly compact longitudinal power transmission.Alternatively, the present invention contemplates thattorque-transmitting mechanisms 32, 34, 36, 38, 40 and 42, are disposedin the other zones as shown in chart (I) below, in accordance with theembodiments of the present invention. An “X” in the chart shown belowindicates that the particular clutch is positionable in any of thereferenced Zones and an “O” indicates that the particular gear is not tobe located in the referenced Zones.

CHART I TORQUE TRANSMITTING ZONES MECHANISM A B C D E 32 X X X ◯ ◯ 34 XX X ◯ ◯ 36 X X X ◯ ◯ 38 X X X X X 40 ◯ X X X X 42 X X X X X

In an alternate embodiment of the present invention, a powertrain 10A isshown in FIG. 2. The corresponding components have been given the samenumerical designation. Powertrain 10A includes a transmission 16A thathas sun gear member 60 that is continuously connected with housing 54through a shaft 93A that traverses zones B and E. Further, as shown inFIG. 2, torque-transmitting mechanism 32 is disposed in zone “B”.Further, torque-transmitting mechanisms 34 and 36 are disposed in zone“C”. The torque-transmitting mechanisms 38, 40 and 42 are disposed inzone “E”. This makes for a fairly compact longitudinal powertransmission. Alternatively, the present invention contemplates thattorque-transmitting mechanisms 32, 34, 36, 38, 40 and 42, are disposedin the other zones as shown in chart (II) below, in accordance with theembodiments of the present invention. An “X” in the chart shown belowindicates that the particular clutch is positionable in any of thereferenced Zones and an “O” indicates that the particular gear is not tobe located in the referenced Zones.

CHART II TORQUE TRANSMITTING ZONES MECHANISM A B C D E 32 X X ◯ ◯ X 34 XX X X ◯ 36 X X X ◯ ◯ 38 X X X X X 40 ◯ X X X X 42 ◯ X X X X

In an alternate embodiment of the present invention, a powertrain 10B,shown in FIG. 3, incorporates the transmission 16B, which includes theplanetary gearsets 26, 28, and 30 and the torque-transmitting mechanisms32, 34, 36, 38, 40 and 42. Planetary gearset 28 is disposed closest towall 50 and planetary gearset 30 is disposed closest to wall 52.Planetary gearset 26 is disposed between planetary gearset 28 and 30.Those torque-transmitting mechanisms that are identical with FIG. 1 havethe same numerical designation.

As shown in FIG. 3, sun gear member 60 is continuously connected withhousing 54 through shaft 93B that traverses zones C and E. Further,torque-transmitting mechanisms 32 and 40 are disposed in zone “C”.Torque-transmitting mechanisms 34 and 36 are disposed in zone “B”.Torque-transmitting mechanisms 38 and 42 are disposed in zone “E”. Thismakes for a fairly compact longitudinal power transmission.

Alternatively, the present invention contemplates thattorque-transmitting mechanisms 32, 34, 36, 38, 40 and 42, are disposedin the other zones as shown in chart (III) below, in accordance with theembodiments of the present invention. An “X” in the chart shown belowindicates that the particular clutch is positionable in any of thereferenced Zones and an “O” indicates that the particular gear is not tobe located in the referenced Zones.

CHART III TORQUE TRANSMITTING ZONES MECHANISM A B C D E 32 X X X ◯ X 34X X ◯ ◯ X 36 X X X ◯ X 38 ◯ X X ◯ X 40 X X X ◯ X 42 ◯ ◯ X X X

In an alternate embodiment of the present invention, a powertrain 10C isshown in FIG. 4. The input and output shafts 20, 24 are supportedthrough end wall 50 to provide a transmission for a front wheel drivevehicle. The corresponding components have been given the same numericaldesignation. Powertrain 10C, shown in FIG. 4, incorporates atransmission 16C, which includes the planetary gearsets 26, 28, and 30and the torque-transmitting mechanisms 32, 34, 36, 38, 40 and 42.Planetary gearset 30 is disposed closest to wall 50 and planetarygearset 26 is disposed closest to wall 52. Planetary gearset 28 isdisposed between planetary gearset 26 and 30. Those torque-transmittingmechanisms that are identical with FIG. 1 have the same numericaldesignation.

As shown in FIG. 4, sun gear member 60 is continuously connected withend wall 52 through a shaft 93C that traverses only zone D.Alternatively, shaft 93C could pass through zone D and connect tohousing 54. Further, torque-transmitting mechanism 34 is disposed inzone “A”. Torque-transmitting mechanism 36 is disposed in zone “B”. Thetorque-transmitting mechanisms 32 and 40 are disposed in zone “C”. Thetorque-transmitting mechanism 38 is disposed in zone “D”. Thetorque-transmitting mechanism 42 is disposed in zone “E”. This makes fora fairly compact transverse power transmission.

Alternatively, the present invention contemplates thattorque-transmitting mechanisms 32, 34, 36, 38, 40 and 42, are disposedin the other zones as shown in chart (IV) below, in accordance with theembodiments of the present invention. An “X” in the chart shown belowindicates that the particular clutch is positionable in any of thereferenced Zones and an “O” indicates that the particular gear is not tobe located in the referenced Zones.

CHART IV TORQUE TRANSMITTING ZONES MECHANISM A B C D E 32 X X X X ◯ 34 XX ◯ ◯ ◯ 36 X X X ◯ ◯ 38 ◯ X X X X 40 ◯ X X X X 42 X X X X X

In an alternate embodiment of the present invention, a powertrain 10Dshown in FIG. 5, which incorporates a transmission 16D. Transmission 16Dincludes the planetary gearsets 26, 28, and 30 and thetorque-transmitting mechanisms 32, 34, 36, 38, 40 and 42. Planetarygearset 26 is disposed closest to wall 50 and planetary gearset 28 isdisposed closest to wall 52. Planetary gearset 30 is disposed betweenplanetary gearset 26 and 28. Those torque-transmitting mechanisms thatare identical with FIG. 1 have the same numerical designation.

As shown in FIG. 5, sun gear member 60 is continuously connected withhousing 54 through a shaft 93D that traverses only zone A & E.Alternatively, shaft 93D could traverse through Zone A only and connectto side wall 50. Further, torque-transmitting mechanism 32 is disposedin zone “B”. Torque-transmitting mechanism 40 is disposed in zone “C”.The torque-transmitting mechanisms 34 and 36 are disposed in zone “D”.The torque-transmitting mechanisms 38 and 42 are disposed in zone “E”.This makes for a fairly compact longitudinal power transmission.

Alternatively, the present invention contemplates thattorque-transmitting mechanisms 32, 34, 36, 38, 40 and 42, are disposedin the other zones as shown in chart (V) below, in accordance with theembodiments of the present invention. An “X” in the chart shown belowindicates that the particular clutch is positionable in any of thereferenced Zones and an “O” indicates that the particular gear is not tobe located in the referenced Zones.

CHART V TORQUE TRANSMITTING ZONES MECHANISM A B C D E 32 X X X ◯ ◯ 34 XX X X X 36 X X X X X 38 X X ◯ ◯ X 40 ◯ X X ◯ ◯ 42 X X X X X

In an alternate embodiment of the present invention, a powertrain 10Eshown in FIG. 6, incorporates a transmission 16E. The input and outputshafts 20, 24 of transmission 16E are supported through end wall 50 toprovide a transmission for a front wheel drive vehicle. Transmission 16Eincludes the planetary gearsets 26, 28, and and the torque-transmittingmechanisms 32, 34, 36, 38, 40 and 42. Planetary gearset 30 is disposedclosest to end wall 50 and planetary gearset 28 is disposed closest towall 52. Planetary gearset 26 is disposed between planetary gearset 28and 30. Those torque-transmitting mechanisms that are identical withFIG. 1 have the same numerical designation.

As shown in FIG. 6, sun gear member 60 is continuously connected withend wall 52 through a shaft 93E that traverses zones C and D. Further,torque-transmitting mechanism 34 is disposed in zone “A”. Thetorque-transmitting mechanisms 32 and 36 are disposed in zone “B”.Further, torque-transmitting mechanism 40 is disposed in zone “D”. Thetorque-transmitting mechanisms 38 and 42 are disposed in zone “E”. Thismakes for a fairly compact transverse power transmission.

Alternatively, the present invention contemplates thattorque-transmitting mechanisms 32, 34, 36, 38, 40 and 42, are disposedin the other zones as shown in chart (VI) below, in accordance with theembodiments of the present invention. An “X” in the chart shown belowindicates that the particular clutch is positionable in any of thereferenced Zones and an “O” indicates that the particular gear is not tobe located in the referenced Zones.

CHART VI TORQUE TRANSMITTING ZONES MECHANISM A B C D E 32 X X ◯ ◯ ◯ 34 XX ◯ ◯ ◯ 36 X X X ◯ ◯ 38 X X X X X 40 ◯ X X X X 42 X X ◯ ◯ X

In an alternate embodiment of the present invention, a powertrain 10Fshown in FIG. 7, incorporates a transmission 16F, which includes theplanetary gearsets 26, 28, and 30 and the torque-transmitting mechanisms32, 34, 36, 38, 40 and 42. Planetary gearset 26 is disposed closest towall 50 and planetary gearset 28 is disposed closest to wall 52.Planetary gearset 30 is disposed between planetary gearset 26 and 28.Those torque-transmitting mechanisms that are identical with FIG. 1 havethe same numerical designation.

As shown in FIG. 7, sun gear member 60 is continuously connected withhousing 54 through a shaft 93F that traverses zones B and E. Further,torque-transmitting mechanism 32 is disposed in zone “B”. Thetorque-transmitting mechanism 40 is disposed in zone “C”. Further,torque-transmitting mechanisms 34 and 36 are disposed in zone “D”. Thetorque-transmitting mechanisms 38 and 42 are disposed in zone “E”. Thismakes for a fairly compact longitudinal transmission.

Alternatively, the present invention contemplates thattorque-transmitting mechanisms 32, 34, 36, 38, 40 and 42, are disposedin the other zones as shown in chart (VII) below, in accordance with theembodiments of the present invention. An “X” in the chart shown belowindicates that the particular clutch is positionable in any of thereferenced Zones and an “O” indicates that the particular gear is not tobe located in the referenced Zones.

CHART VII TORQUE TRANSMITTING ZONES MECHANISM A B C D E 32 X X ◯ ◯ X 34X ◯ ◯ X X 36 X ◯ ◯ X X 38 X X ◯ ◯ X 40 ◯ X X ◯ X 42 ◯ X X ◯ X

In an alternate embodiment of the present invention, a powertrain 10Gshown in FIG. 8, incorporates a transmission 16G. The input and outputshafts 20, 24 of transmission 16G are supported through end wall 50 toprovide a transmission for a front wheel drive vehicle. Transmission 16Gincludes the planetary gearsets 26, 28, and and the torque-transmittingmechanisms 32, 34, 36, 38, 40 and 42. Planetary gearset 28 is disposedclosest to wall 50 and planetary gearset 26 is disposed closest to wall52. Planetary gearset 30 is disposed between planetary gearset 26 and28. Those torque-transmitting mechanisms that are identical with FIG. 1have the same numerical designation.

As shown in FIG. 8, sun gear member 60 is continuously connected withhousing 54 through a shaft 93G that traverses zones D and E.Alternatively, shaft 93G could traverse through zone E only and connectto sidewall 52. Further, torque-transmitting mechanisms 34 and 36 aredisposed in zone “A”. The torque-transmitting mechanism 40 is disposedin zone “B”. Further, torque-transmitting mechanism 32 is disposed inzone “C”. The torque transmitting mechanism 38 is disposed in zone “D”.The torque-transmitting mechanism 42 is disposed in zone “E”. This makesfor a fairly compact transverse power transmission.

Alternatively, the present invention contemplates thattorque-transmitting mechanisms 32, 34, 36, 38, 40 and 42, are disposedin the other zones as shown in chart (VIII) below, in accordance withthe embodiments of the present invention. An “X” in the chart shownbelow indicates that the particular clutch is positionable in any of thereferenced Zones and an “O” indicates that the particular gear is not tobe located in the referenced Zones.

CHART VIII TORQUE TRANSMITTING ZONES MECHANISM A B C D E 32 X X X ◯ ◯ 34X X ◯ ◯ X 36 X X ◯ ◯ X 38 ◯ ◯ X X X 40 ◯ X X ◯ X 42 ◯ X X X X

In an alternate embodiment of the present invention, a powertrain 10Hshown in FIG. 9, incorporates a transmission 16H. Transmission 16Hincludes the planetary gearsets 26, 28, and 30 and thetorque-transmitting mechanisms 32, 34, 36, 38, 40 and 42. Planetarygearset 28 is disposed closest to wall 50 and planetary gearset 30 isdisposed closest to wall 52. Planetary gearset 26 is disposed betweenplanetary gearset 28 and 30. Those torque-transmitting mechanisms thatare identical with FIG. 1 have the same numerical designation.

As shown in FIG. 9, sun gear member 60 is continuously connected withhousing 54 through a shaft 93H that traverses zones C and E. Further,torque-transmitting mechanism 40 is disposed in zone “A”. Thetorque-transmitting mechanisms 34, 36 and 38 are disposed in zone “B”.Further, torque-transmitting mechanism 32 is disposed in zone “C”. Thetorque-transmitting mechanism 42 is disposed in zone “E”. This makes fora fairly compact longitudinal power transmission.

Alternatively, the present invention contemplates thattorque-transmitting mechanisms 32, 34, 36, 38, 40 and 42, are disposedin the other zones as shown in chart (IX) below, in accordance with theembodiments of the present invention. An “X” in the chart shown belowindicates that the particular clutch is positionable in any of thereferenced Zones and an “O” indicates that the particular gear is not tobe located in the referenced Zones.

CHART IX TORQUE TRANSMITTING ZONES MECHANISM A B C D E 32 X X X ◯ X 34 XX X ◯ X 36 X X X ◯ X 38 ◯ X X X X 40 X X X X X 42 ◯ ◯ X X X

While the best modes for carrying out the invention have been describedin detail, it is to be understood that the terminology used is intendedto be in the nature of words and description rather than of limitation.Those familiar with the art to which this invention relates willrecognize that many modifications of the present invention are possiblein light of the above teachings. It is, therefore, to be understood thatwithin the scope of the appended claims, the invention may be practicedin a substantially equivalent way other than as specifically describedherein.

1. A transmission comprising: an input member; an output member; atransmission housing having a first wall, a second wall, and a thirdwall extending between the first and second walls; a first, second, andthird planetary gear set disposed within the transmission housing,wherein the first planetary gear set is adjacent the first wall, thesecond planetary gear set is adjacent second wall, and the thirdplanetary gear set is between the first and second planetary gear sets,each planetary gear set having a sun gear member, a ring gear member,and a planet carrier member supporting a plurality of planet gears eachconfigured to intermesh with both the sun gear member and the ring gearmember, wherein the output member is continuously interconnected withthe planet carrier member of the third planetary gear set, wherein thering gear member of the first planetary gear set is permanently coupledto the sun gear member of the second planetary gear set, and wherein thesun gear member of the first planetary gear set is permanently coupledto the transmission housing; wherein the transmission housing has afirst area defined radially inward from an outer periphery of theplanetary gear sets and axially bounded by the first wall and the firstplanetary gear set, a second area defined radially inward from the outerperiphery of the planetary gear sets and axially bounded by the firstand third planetary gear sets, a third area defined radially inward fromthe outer periphery of the planetary gear sets and axially bounded bythe second and third planetary gear sets, a fourth area defined radiallyinward from the outer periphery of the planetary gear sets and axiallybounded by the second planetary gear set and the second wall, and afifth area defined radially inward from the third wall and radiallyoutward from the outer periphery of the planetary gear sets and axiallybounded by the first wall and the second wall; a first clutchselectively engageable to interconnect the input member with the planetcarrier member of the first planetary gear set; a second clutchselectively engageable to interconnect the input member with the ringgear member of the second planetary gear set and the sun gear member ofthe third planetary gear set; a third clutch selectively engageable tointerconnect the input member with the planet carrier member of thesecond planetary gear set; a fifth clutch selectively engageable tointerconnect the planet carrier member of the second planetary gear setwith the ring gear member of the third planetary gear set; a fourthclutch selectively engageable to interconnect the planet carrier memberof the first planetary gear set with the ring gear member of the thirdplanetary gear set; a brake selectively engageable to interconnect thering gear member of the third planetary gear set to the transmissionhousing; wherein the first clutch is located in at least one of thefirst, second, and fifth areas, the second clutch is located in at leastone of the first, fourth, and fifth areas, the third clutch is locatedin at least one of the first, fourth, and fifth areas, the fourth clutchis located in at least one of the first, second, and fifth areas, thefifth clutch is located in at least one of the second, third, and fifthareas, and the brake is located in at least one of the second, third,and fifth areas; and wherein the clutches and brake are selectivelyengageable to establish at least eight forward speed ratios and at leastone reverse speed ratio between the input member and the output member.2. The transmission of claim 1 wherein the first clutch is located inthe second area, the second clutch is located in the fourth area, thethird clutch is located in the fourth area, the fourth clutch is locatedin the fifth area, the fifth clutch is located in the third area, andthe brake is located in the fifth area.
 3. The transmission of claim 1wherein the first clutch is located within the first area.
 4. Thetransmission of claim 1 wherein the first clutch is located within thesecond area.
 5. The transmission of claim 1 wherein the first clutch islocated within the fifth area.
 6. The transmission of claim 1 whereinthe second clutch is located within the first area.
 7. The transmissionof claim 1 wherein the second clutch is located within the fourth area.8. The transmission of claim 1 wherein the second clutch is locatedwithin the fifth area.
 9. The transmission of claim 1 wherein the thirdclutch is located within the first area.
 10. The transmission of claim 1wherein the third clutch is located within the fourth area.
 11. Thetransmission of claim 1 wherein the third clutch is located within thefifth area.
 12. The transmission of claim 1 wherein the fourth clutch islocated within the first area.
 13. The transmission of claim 1 whereinthe fourth clutch is located within the second area.
 14. Thetransmission of claim 1 wherein the fourth clutch is located within thefifth area.
 15. The transmission of claim 1 wherein the fifth clutch islocated within the second area.
 16. The transmission of claim 1 whereinthe fifth clutch is located within the third area.
 17. The transmissionof claim 1 wherein the fifth clutch is located within the fifth area.18. The transmission of claim 1 wherein the brake is located within thesecond area.
 19. The transmission of claim 1 wherein the brake islocated within the third area.
 20. The transmission of claim 1 whereinthe brake is located within the fifth area.